CN109420388B

CN109420388B - Sack cleaner and catalytic cracking catalyst preparation system

Info

Publication number: CN109420388B
Application number: CN201710780724.6A
Authority: CN
Inventors: 张杰潇; 张万虹; 李家兴; 严加松; 田辉平
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2017-09-01
Filing date: 2017-09-01
Publication date: 2020-10-27
Anticipated expiration: 2037-09-01
Also published as: CN109420388A

Abstract

The invention relates to a bag-type dust collector and a catalytic cracking catalyst preparation system, wherein the bag-type dust collector comprises a shell, a partition plate arranged in the shell, a plurality of bag supporting tubes and a bag wrapped outside each bag supporting tube, and filter holes are formed in the tube walls of the bag supporting tubes; the inner space of the shell is divided into an upper cavity and a lower cavity by the partition plate, the shell where the upper cavity is located is provided with an air outlet, and the shell where the lower cavity is located is provided with a feed inlet and a discharge outlet; the discharging device is characterized in that a discharging pipe is arranged in the lower cavity, one end of the discharging pipe is connected with the feeding hole, the other end of the discharging pipe extends downwards towards the discharging hole, and a ventilation hole is formed in the pipe wall of the discharging pipe. The bag-type dust remover and the catalytic cracking catalyst preparation system provided by the disclosure have good dust removal effect.

Description

Sack cleaner and catalytic cracking catalyst preparation system

Technical Field

The disclosure relates to a bag-type dust collector and a catalytic cracking catalyst preparation system.

Background

The catalytic cracking molecular sieve and the catalyst powder are widely applied in various fields of chemical industry, wherein the powder is generally carried and conveyed by gas, and tail gas for conveying the powder generally needs to be subjected to dust removal treatment. For example, in the chemical field, molecular sieves and catalysts for catalytic cracking are subjected to roasting, drying, conveying, spraying and other processes in the preparation process, and in the processes, no matter the molecular sieves and the catalysts are generally subjected to multiple dust removal treatments, the emission of the gases as the gases for conveying can meet the environmental protection requirement.

At present, most of powder containing dust is filtered by adopting a bag-type dust collector, the bag-type dust collector is a key device for gas-solid separation, the working principle of the bag-type dust collector is that air flow carries the dust-containing powder to be introduced into the bag-type dust collector, the dust-containing powder enters a bag in the bag-type dust collector through induced air to be filtered, the coarse powder is firstly settled downwards, the dust is adsorbed on the bag, the air is carried away from the bag-type dust collector, and the powder achieves the dust removal effect. However, the prior bag-type dust collector is generally arranged behind the roasting furnace or the airflow drying equipment, and the temperature of materials passing through the roasting furnace and the airflow drying equipment is too high, so that the bag is easy to burn, the treatment capacity of the materials is limited, if the flow of the conveying gas is increased, the temperature of the materials can be reduced, the sintering probability of the cloth bag is reduced, the incomplete dust removal of the cloth bag dust remover can be caused due to the excessive treatment capacity, meanwhile, the air flow distribution is not uniform, the air flow with high wind speed easily washes the lower opening of the cloth bag to cause serious abrasion, the cloth bag can not be normally used, a great deal of dust is not absorbed by the cloth bag, a great deal of dust is introduced into the air to cause the environmental protection problem, therefore, a bag-type dust remover with large treatment capacity, small volume, low cost, small temperature influence and excellent dust removal effect needs to be developed at the present stage to meet the industrial production requirements of the catalytic cracking molecular sieve and the catalyst.

Chinese patent CN200710201872.4 proposes a bag-type dust collector and a manufacturing method thereof, the bag-type dust collector is provided with an airflow channel communicated with a dust-containing gas inlet of the bag-type dust collector at one side in a box body of the existing bag-type dust collector, so that an outlet of the airflow channel is communicated with a dust hopper below the bag-type dust collector, and two airflow baffles which are parallel to each other are arranged in the dust hopper, and the airflow baffles are parallel to a box body panel connected with one side of the gas inlet; the dust-containing gas introduced into the middle box body is flushed into the ash bucket under the guidance of the airflow channel, so that the direct flushing of the dust-containing gas on the filter bag of the bag-type dust collector is avoided; the dust-containing gas rushing into the dust hopper is uniformly ascended to the filter bag area in the middle box body after being blocked by the division of the airflow baffle, the gas penetrates through the filter bag to be discharged from the upper box body under the action of negative pressure, the dust is uniformly adsorbed on the filter bag, and the adsorption performance and the purification effect of the bag-type dust remover can be improved by the dust uniformly adsorbed on the filter bag. But the patent has the problems that the high-temperature powder sinters the filter bag at high temperature and breaks the blockage.

Chinese patent CN200920016914.1 provides a sack cleaner sack protection device, is equipped with an "L" shape deep bead at sack cleaner ash bucket air intake, and the deep bead passes through the leg joint on the ash bucket inner wall, directly falls into the ash bucket after making the large granule dust collide, and the small granule dust direction of change evenly gets into the dust remover, filters through the sack, realizes discharge to reach standard. The air flow is prevented from directly washing the cloth bag, so that the service life of the cloth bag is greatly prolonged, the replacement times are reduced, the labor intensity of maintenance personnel is reduced, the expense is reduced, and the stable operation of the dust remover is ensured. The structure is simple, the cost is low, and the device can be reformed by itself, and has obvious social benefit and popularization value. Although the patent can reduce the air flow with dust through the L-shaped wind shield to directly wash the air bag, if the air bag is used for treating high-temperature powder, most of the high-temperature powder still directly contacts the cloth bag, so that the service life of the cloth bag is shortened.

Chinese patent CN201410786239.6 provides a rotary lower air inlet type bag dust collector, which comprises a vertically arranged frame, a bag dust collector body vertically installed above the frame, and an overhaul platform installed between the bag dust collector body and the frame. The bag-type dust collector of this patent is convenient to maintain, but does not solve the problem of life-span improvement.

Disclosure of Invention

The bag-type dust remover and the catalytic cracking catalyst preparation system can treat materials with high temperature.

In order to achieve the purpose, the disclosure provides a bag-type dust collector, which comprises a shell, and a partition plate and a plurality of bag supporting tubes which are arranged in the shell, wherein a bag is wrapped outside each bag supporting tube, and the tube wall of each bag supporting tube is provided with a filtering hole; the inner space of the shell is divided into an upper cavity and a lower cavity by the partition plate, the shell where the upper cavity is located is provided with an air outlet, and the shell where the lower cavity is located is provided with a feed inlet and a discharge outlet; the partition plate is provided with a plurality of openings; each cloth bag supporting tube is connected with the top wall of the shell, the upper end of each cloth bag supporting tube is sealed, the lower end of each cloth bag supporting tube is arranged above one opening, a cloth bag wrapped outside the corresponding cloth bag supporting tube is connected with the inner periphery of the opening in a sealing mode, and the feed inlet and the air outlet are communicated with the opening, the cloth bag supporting tubes and the cloth bag in sequence in the shell; the discharging device is characterized in that a discharging pipe is arranged in the lower cavity, one end of the discharging pipe is connected with the feeding hole, the other end of the discharging pipe extends downwards towards the discharging hole, and a ventilation hole is formed in the pipe wall of the discharging pipe.

The present disclosure also provides a catalytic cracking catalyst preparation system, the system comprising: the device comprises a gelatinizing unit, a spray dryer, a cyclone separator, a first bag-type dust remover and a first roasting unit, wherein the first bag-type dust remover is the bag-type dust remover provided by the disclosure; the gelatinizing unit is provided with a material inlet and a material outlet, the spray dryer is provided with a material inlet and a catalyst outlet, and the cyclone separator is provided with a catalyst inlet, a coarse powder outlet and a fine powder outlet; the material inlet of the spray dryer is positioned at the downstream of the material outlet of the colloid forming unit, the catalyst inlet of the cyclone separator is positioned at the downstream of the catalyst outlet of the spray dryer, the feed inlet of the first bag-type dust collector is positioned at the downstream of the coarse powder outlet of the cyclone separator, and the inlet of the first roasting unit is positioned at the downstream of the discharge outlet of the first bag-type dust collector.

The bag-type dust remover and the catalytic cracking catalyst preparation system using the bag-type dust remover have the following advantages:

1. the shell of the bag-type dust collector disclosed by the invention is internally provided with the partition board which divides the inner space of the bag-type dust collector into the upper cavity and the lower cavity, so that powder carried by air flow can collide with the partition board firstly for separation, the separation pressure and the abrasion degree of a bag supporting pipe and a bag are reduced, the equipment cost is reduced, the dust collection efficiency is improved, and the powder carried by the air flow is sequentially contacted with the partition board and the bag supporting pipe firstly, so that most of high-temperature powder can be prevented from directly contacting the bag, and the bag-type dust collector is slightly;

2. the blanking pipe is arranged in the bag-type dust collector, so that materials with the catalyst from the feeding hole can be effectively separated in the blanking pipe, the abrasion of the inner wall of the shell and other parts is reduced, the dust collection efficiency and the treatment capacity can be improved, the volume of the bag-type dust collector is reduced, and the influence of temperature on the bag-type dust collector is further reduced;

3. the gas discharged by the bag-type dust collector disclosed by the invention can reach the environmental protection standard and meet the industrial production requirements of catalytic cracking molecular sieves and catalysts.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

fig. 1 is a schematic structural diagram of a specific embodiment of a bag-type dust collector provided by the present disclosure.

FIG. 2 is a schematic structural view of one embodiment of a separator provided by the present disclosure.

FIG. 3 is a schematic diagram of one embodiment of a catalytic cracking catalyst preparation system provided by the present disclosure.

FIG. 4 is a schematic diagram of a particular embodiment of a fines separator provided by the present disclosure.

FIG. 5 is an axial cross-sectional view of the fines separator of FIG. 4.

FIG. 6 is a radial cross-sectional view of one embodiment of a fines separator (comprising two cylinders) provided by the present disclosure.

Description of the reference numerals

1 housing 11 upper chamber 12 lower chamber

13 cylinder section and 14 cone section

2 feed inlet, 3 air outlet and 4 discharge outlets

51 cloth bag support tube 52 cloth bag

6 opening of the partition board 61

7 blanking pipe 91 vent of wind-guard sheet 9

A gelatinizing unit, B spray dryer and C cyclone separator

D1 first bag dust collector D2 second bag dust collector

E1 first firing Unit E2 second firing Unit

F fines separator 300 housing 301 fines separator inlet

302 fine powder outlet 303 coarse powder outlet 304 catalyst agitating mechanism

305 cylinder 306 screening channel 307 agitation plates

308 axial rod 309 annular rod 310 spindle

311 column 312 powder outlet 313 cylinder section

314 conical segment

G1 molecular sieve ion exchange unit G2 filtration unit G3 flash drying unit

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

In the present disclosure, unless otherwise stated, the use of directional words such as "upper, lower, bottom, top" is generally defined under normal operation of the bag-type dust collector provided by the embodiments of the present disclosure, and specifically, reference may be made to the drawing direction of fig. 1, and "inner and outer" refer to the inner and outer of the profile of the corresponding component. The distance between two parts is the length of the shortest connection between two parts.

According to the bag-type dust collector provided by the disclosure, the space in the shell is divided into an upper part and a lower part by the partition plate 6, the bag supporting pipes are placed in the upper space, and each bag supporting pipe wraps a bag.

As shown in fig. 1, the present disclosure provides a bag-type dust collector, which includes a housing 1, and a partition plate 6 and a plurality of bag support tubes 51 disposed in the housing 1, wherein a bag 52 is wrapped around the outer side of each bag support tube 51, and the walls of the bag support tubes 51 are provided with filter holes; the partition plate 6 divides the inner space of the shell 1 into an upper cavity 11 and a lower cavity 12, the shell 1 where the upper cavity 11 is located is provided with an air outlet 3, and the shell 1 where the lower cavity 12 is located is provided with a feeding hole 2 and a discharging hole 4; the partition board 6 is provided with a plurality of openings 61; each cloth bag supporting pipe 51 is connected with the top wall of the shell 1, the upper end of each cloth bag supporting pipe 51 is sealed, the lower end of each cloth bag supporting pipe 51 is arranged above one opening 61, a cloth bag 52 wrapped outside the corresponding cloth bag supporting pipe 51 is connected with the inner circumference of the opening 61 in a sealing mode (the sealing mode means that the connecting part does not penetrate powder), and the feeding port 2 and the air outlet 3 are communicated with the opening 61, the cloth bag supporting pipes 51 and the cloth bag 52 in the shell 1 in sequence; a discharging pipe 9 is arranged in the lower cavity 12, one end of the discharging pipe 9 is connected with the feeding hole 2, the other end of the discharging pipe extends downwards towards the discharging hole, and a ventilation hole 91 is formed in the pipe wall of the discharging pipe 9.

In one embodiment, each opening of the partition 6 is connected with a cloth bag supporting pipe cloth bag, and each opening has a distance with the cloth bag supporting pipe, so that powder falling in the cloth bag can conveniently fall through the distance. The connection between the cloth bag support tube and the opening 61 prevents the powder in the gas from directly entering the upper chamber 11 from the connection, and the powder gas in the gas firstly enters the cloth bag support tube and then passes through the wrapped cloth bag to enter the upper chamber 11.

Taking the dust removal of a catalytic cracking catalyst (hereinafter referred to as catalyst) as an example, the specific working mode of the bag-type dust remover disclosed by the invention is as follows: as shown in figure 1, the feeding amount of 100-500 ℃ high-temperature catalyst powder is 40-400m at 1000-10000Kg/h³/h(STP，0℃(273K)、1.01×10⁵Pa) of 15-30 Kg/(m) of air³Air) enters and enters from the inlet port 2 of the housing 1In the blanking pipe 9 connected with the material 2, catalyst particles in the blanking pipe collide with the side wall of the blanking pipe and settle, so that air current carrying partial catalyst flows upwards from the vent hole 91 on the side wall of the blanking pipe 9, most of the catalyst in the blanking pipe 9 falls into the discharge port 4 along the blanking pipe 9, and is sent out of the bag-type dust collector through the discharge port 4. The catalyst rising with the air flow undergoes further settling separation in the lower chamber 12 of the housing 1, the separated catalyst also falling further into the outlet 4. The catalyst and the air which continuously rise collide with the partition plate 6 at first, most of the catalyst falls under the action of the partition plate 6, a small part of the catalyst and the air pass through the opening 61 formed in the partition plate 6 and rise into the cloth bag support tube 51, the catalyst falls after colliding with the cloth bag support tube 51, the air carrying the catalyst passes through the filtering hole of the cloth bag support tube 51 and is further filtered by the cloth bag 52 wrapped on the outer side of the cloth bag support tube, most of the catalyst is filtered and agglomerated, then slides downwards along the gap between the cloth bag support tube and the cloth bag and falls through the opening 61, the air filtered by the cloth bag is led out of the cloth bag dust collector under the action of an induced draft fan arranged at the air outlet 3 in the upper chamber, the air lead-out amount of the induced draft fan is the same as the air lead-in amount, and.

The method introduces a catalyst and air into a bag-type dust collector and then carries out dust removal treatment on a discharging pipe, a partition plate, a bag supporting pipe, a bag and other parts in sequence, so that the discharged gas meets the environmental protection standard, the arranged discharging pipe and the partition plate can effectively reduce the abrasion and high temperature action of the catalyst on the bag and the bag supporting pipe, prolong the service life of the bag, improve the dust removal efficiency and treatment capacity, reduce the volume of the bag-type dust collector, reduce the secondary carrying and rising of the separated catalyst near the bag, and ensure that the discharged gas meets the smoke (powder) dust concentration of less than 100mg/m in the emission standard of industrial furnace atmospheric pollutants (GB9078-1996) formulated by the air pollution control Law of the people's republic of China³And (5) primary environmental protection standard.

The blanking pipe can be a pipe with various shapes, for example, the blanking pipe can be L-shaped, S-shaped, or C-shaped, and in order to further improve the space utilization efficiency in the lower chamber 12, as shown in fig. 1, the blanking pipe 9 can be a spiral coil pipe, the spiral coil pipe can effectively utilize the whole space in the housing, increase the residence time of powder in the bag-type dust remover, and improve the effect of the bag-type dust remover, and in addition, the spiral coil pipe can increase the displacement of the catalyst and air in the horizontal direction in the housing, increase the collision area between the inner wall of the blanking pipe and the catalyst, effectively reduce the speed of the catalyst, and is beneficial to the sedimentation of the catalyst. The spiral coil is preferably arranged to utilize the space of the lower chamber 12 to the maximum without causing the catalyst in the spiral coil to be blocked, for example, the spiral axis of the spiral coil may be arranged in the vertical direction, the helix angle may be 20-45 °, the inner diameter (diameter, the same below) may be 0.2-0.5m, the expansion length may be 10-40m, the aperture size of the vent hole 91 on the spiral coil may be 0.05-0.2m, the aperture ratio (the ratio of the total area of the vent hole 91 on the outer surface of the spiral coil to the outer surface of the spiral coil) may be 60-80%, the material of the spiral coil may be stainless steel, reinforced concrete or copper, etc., the inner surface of the spiral coil may be provided with a wear-resistant lining (such as a cement layer), and the spiral coil may be provided with blowback air at a distance to prevent the catalyst from blocking the. In addition, for the convenience of connection with the feed inlet, as shown in fig. 1, the upper portion of the spiral coil may be provided with a horizontal pipe inserted into the feed inlet for introducing air and catalyst, and the ratio of the length of the horizontal pipe to the development length of the spiral coil may be 1: (4-16). Because catalyst and air are decurrent screw motion in spiral coil, in order to improve the falling speed of catalyst in the spiral coil exit, spiral coil's lower part can set up one section vertical pipe to in convenient guide catalyst gets into discharge gate 4, the length of this vertical pipe and the ratio of spiral coil development length can be 1: (20-80).

In order to improve the blanking efficiency at the bottom of the blanking tube, as shown in fig. 1, the other end of the blanking tube 9 may be disposed right above the discharge port 4 at intervals, so as to reduce the frictional resistance between the outlet of the blanking tube and the catalyst, and also increase the accumulation space after the catalyst leaves the blanking tube, thereby preventing the catalyst from blocking the outlet of the blanking tube and the outlet of the blanking tube due to the direct connection between the blanking tube and the discharge port. According to the catalyst feeding amount and the air conveying amount, the distance between the blanking pipe and the discharge port can be controlled to prevent the catalyst from being blocked under the condition that the longest blanking pipe is arranged, for example, the vertical distance between the blanking pipe 9 and the discharge port 4 accounts for the vertical distance between the feeding port 2 and the discharge port 4, and the ratio of the vertical distance between the feeding port 2 and the discharge port 4 can be (0.05-0.2): 1.

catalyst and air entering the shell through the feed port are divided into two parts, most of the catalyst leaves the shell through the discharge port, most of the air leaves the shell through the air outlet, in order to improve the flowing distance of the air in the shell and increase the collision probability of the catalyst carried in the air and each part in the shell, as shown in figure 1, the feed port 2 can be positioned on the side wall of the shell, the air outlet 3 can be positioned on the top wall of the shell, an angle formed by a connecting line of the distance between the feed port 2 and the air outlet 3 and a horizontal plane can be 45-70 degrees, preferably, the connecting line of the distance between the feed port 2 and the air outlet 3 penetrates through the central axis of the shell, so that the distance between the feed port and the air outlet is longest, and the dust.

The effect of baffle lies in the catalyst that the collision rises on the one hand, make its whereabouts, on the other hand is convenient for fixed sack stay tube 51 and sack 52, the one end of sack stay tube 51 can welded seal on the roof of casing 1, the other end can set up in the baffle top for the interval, the one end sealing connection of sack is on the roof of casing 1, other end sealing connection is on the baffle, there is the distance between the lower extreme of sack stay tube and the baffle, thereby make things convenient for behind the sack absorption certain amount of catalyst, the catalyst reunion falls down to the cavity down, and the catalyst dust that rises from trompil 61 most can get into in advance in the sack stay tube and filter the back and get into in the sack again, thereby the filter pressure of sack has effectively been alleviated, the. The inner diameter of the cloth bag supporting tube can be 8-160mm, the outer diameter can be 10-200mm, the length can be 1.5-4m, the inner diameter of the cloth bag (the inner diameter of a hollow cylinder formed when the cloth bag is inflated) can be 10-220mm, the height is 2-5m, the thickness of the separator can be 0.5-20mm, and the ratio of the inner diameter of the cloth bag to the outer diameter of the cloth bag supporting tube is 1.05-1.2; as shown in fig. 2, the diameter of the openings 61 may be 20-500mm, and the opening ratio of the separator (the ratio of the sum of the areas of all the openings 61 on the bottom surface of the separator to the area of the bottom surface of the separator) may be 40-60%.

According to the specific implementation mode, a manhole is arranged in a shell where the upper cavity is located, so that maintenance personnel can conveniently enter the shell to replace the cloth bag and maintain damaged parts.

In order to increase the collision area of the partition plate with the catalyst carried in the air, as shown in fig. 1, the partition plate 6 may be arranged to be inclined so as to gradually rise from the side of the feed port 2 toward the side opposite to the feed port 2 in the housing 1, for example, the angle of the bottom surface of the partition plate 6 with respect to the horizontal plane ranges from 20 to 60 °. Because the induced air effect of air outlet to the air increases along feed inlet to the air outlet gradually, consequently, the air rising speed that is close to the feed inlet side is less, and the air rising speed that is close to the relative one side of feed inlet is great, and sets up the baffle with slope can make the baffle lower surface evenly act on with the catalyst that carries in the air, increases the collision area of catalyst on the one hand, improves separation efficiency, and on the other hand prevents that the baffle local wear is too big, and reduces baffle life.

In order to collide and separate the catalyst having a horizontal movement speed due to the disorder of the movement of the catalyst, the partition plate 6 may be protruded with a wind shield 7 downward as shown in fig. 1, and the wind shield 7 may have a strip structure vertically extending downward from the bottom surface of the partition plate 6, the strip structure may have a length of 0.2 to 0.5m and a width of 0.1 to 0.8m, and may be disposed at a position below the edge of the opening 61 provided in the partition plate 6. The wind shield plate in cooperation with the partition plate can effectively increase and decrease the speed of the catalyst in the vertical and horizontal directions, and facilitate the introduction of air into the openings 61.

In order to facilitate the catalyst to enter the discharge port and leave the shell, as shown in fig. 1, the shell 1 may include a cylindrical section 13 and a conical section 14 which are arranged up and down, the feed port 2 is located on the side wall of the cylindrical section 13, the discharge port 4 may be arranged at the bottom of the conical section 14, and the conical angle of the conical section 14 may be 45-70 °. The conical barrel section is arranged to effectively prevent the catalyst from being accumulated at the bottom of the shell. In addition, in order to reasonably distribute the volumes of the upper chamber and the lower chamber and reasonably set the lengths of the cloth bag and the cloth bag supporting tube in the upper chamber and the length of the discharging tube in the lower chamber, the ratio of the vertical distance between the feeding port 2 and the air outlet 3 to the vertical distance between the feeding port 2 and the discharging port 4 may be 1: (1-4).

As shown in fig. 3, the present disclosure also provides a catalytic cracking catalyst preparation system, comprising: the device comprises a gelling unit A, a spray dryer B, a cyclone separator C, a first bag-type dust remover D1 and a first roasting unit E1, wherein the first bag-type dust remover is the bag-type dust remover provided by the disclosure; the device comprises a gelatinizing unit A, a cyclone separator C, a spray dryer B and a spray dryer C, wherein the gelatinizing unit A is provided with a material inlet and a material outlet, the spray dryer B is provided with a material inlet and a catalyst outlet, and the cyclone separator C is provided with a catalyst inlet (a catalyst inlet conveyed by gas), a coarse powder outlet (a catalyst outlet separated by cyclone) and a fine powder outlet (an outlet of gas carrying a small amount of catalyst); the material inlet of the spray dryer B is positioned at the downstream of the material outlet of the gelling unit A, the catalyst inlet of the cyclone separator C is positioned at the downstream of the catalyst outlet of the spray dryer B, the feed inlet of the first bag-type dust collector D1 is positioned at the downstream of the coarse powder outlet of the cyclone separator C, and the inlet of the first roasting unit E1 is positioned at the downstream of the discharge outlet of the first bag-type dust collector D1. The first bag-type dust collector is used for removing air conveying coarse powder in the separation cyclone separator C, so that the coarse powder can be conveyed to the first roasting unit through the screw, explosion caused by overlarge air inlet amount of roasting equipment is prevented, and the conveyed air can reach the discharge standard. It should be noted that "downstream" in the present disclosure generally refers to: if the product from the outlet of the device a is fed further to the inlet of the device B, the inlet of the device B is located downstream of the outlet of the device a, the inlet of the same device may be located downstream of the outlets of a plurality of devices, and the outlet of the same device may be located upstream of the inlets of a plurality of devices.

The specific operation steps for preparing the catalytic cracking catalyst by adopting the system can comprise: feeding a catalytic cracking catalyst raw material into a gelling unit A for gelling, feeding a material obtained by gelling into a spray dryer B for spray drying, feeding the obtained formed catalyst into a cyclone separator for cyclone separation, then feeding the formed catalyst into a first bag-type dust collector D1 for dust removal, then feeding the formed catalyst into a first roasting unit E1 for roasting, or directly feeding the formed catalyst from the spray dryer B into a first bag-type dust collector D1 for dust removal, then feeding the formed catalyst into a first roasting unit E1 for roasting, and optionally washing, drying, ion exchange and other steps of the roasted formed catalyst. The catalytic cracking catalyst feedstock may include clays, molecular sieves, binders and the like well known to those skilled in the art, the clays may include one or more of kaolin, halloysite, montmorillonite, diatomaceous earth, halloysite, pseudohalloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite, the molecular sieves may include Y-type molecular sieves, modified Y-type molecular sieves or type-selective molecular sieves including ZSM-5, beta molecular sieves and the like, the binders may include acidified pseudoboehmite, silica sol, alumina sol or silica alumina gel, magnesium alumina sol, phosphor alumina gel and the like. The material obtained in the gelling process refers to a mixture obtained by mixing a catalytic cracking catalyst raw material and water, and is used for feeding into a spray dryer for spray drying, the gelling is well known to those skilled in the art, and the details of the disclosure are not repeated. In one embodiment, the gelling process of the present disclosure comprises mixing a molecular sieve, a binder, a clay, and water, and slurrying the resulting mixture for more than 15 minutes, such as 30-60 minutes, to form a mass; the slurry preferably has a solid content of 5 to 50 wt%, more preferably 20 to 45 wt%.

In one embodiment, for better utilization of the spray dried catalyst, the system further comprises a fines separator F, comprising a housing 300, the housing 300 has an inlet 301 for a fine powder separator, said housing 300 further having an outlet 302 for fine powder from the fine powder separator at the upper part of the housing, an outlet 303 for coarse powder from the fine powder separator at the bottom of the housing and an outlet 312 for medium powder from the fine powder separator at the middle part of the housing, and at least one coaxial cylinder 305 rotatably installed in the housing 300 along a vertical axis is installed in the housing 300, and sidewalls of the cylinders 305 and sidewalls of the outermost cylinders 305 and sidewalls of the housing 300 are spaced apart, a plurality of screening channels 306 are respectively distributed on all the cylinder bodies 305 along the axial direction and the circumferential direction, and inwards-protruding stirring sheets are fixed on the inner walls of all the cylinder bodies 305; the fines separator inlet 301 of the fines separator F is located downstream of the fines outlet of the cyclone C; the inlet of the first roasting element E1 is located downstream of the fines separator coarse powder outlet 303. The system provided by the disclosure can realize preparation and forming of the catalytic cracking catalyst, can accurately screen catalytic cracking catalyst particles with different particle size ranges by using the fine powder separator, can perform colloid re-utilization on the fine powder particles, reduces pollution of the fine powder to the environment, and improves the catalyst yield and the raw material utilization rate by recycling the coarse powder particles after grinding treatment.

In the fine powder separator, as shown in fig. 4-6, the catalyst microspheres to be separated (fine powder separated by cyclone and/or sprayed catalyst) enter the housing 300 from the fine powder separator inlet 301 by gravity or carried by gas, and each entering catalyst microsphere to be separated can make downward parabolic motion under the action of self gravity, inertia force and/or gas carrying, so that part of the catalyst microspheres enter the cylinder 305 through the sieving channel 306, and if a plurality of coaxial cylinders are provided, the catalyst microspheres have sufficient horizontal velocity to enter the innermost cylinder from the outermost cylinder. The separation of the catalyst microspheres can be realized by a person skilled in the art by controlling the interaction between the strength of the upward cyclone generated by the cylinder and the stirring sheet and the self gravity of the catalyst microspheres to be separated. The catalyst microspheres with smaller particle size easily move upwards and rise to a certain height to collide with the inner wall of the shell to sink, and at this time, if the air in the fine powder separator (the air generally enters the fine powder separator from the fine powder separator inlet 301 and also enters the fine powder separator from other inlets) leaves the fine powder separator from the fine powder outlet 302 of the fine powder separator at the upper part of the shell 300 or the medium powder outlet 312 of the fine powder separator at the middle part, the catalyst microspheres near the fine powder outlet 302 or the medium powder outlet 312 are carried out of the fine powder separator (a micro-negative pressure air inducing device can be arranged at the fine powder outlet 302 and the medium powder outlet 312, and the pressure of the device can be set according to actual conditions to separate the fine powder and the medium powder required to be separated); the catalyst microspheres with larger particle sizes easily move downwards and towards the inner wall of the shell, so that the catalyst microspheres directly settle to the bottom of the shell 300 in the cylinder body 305 or directly fall to the bottom of the shell 300 after colliding with the inner wall of the shell, and are sent out of the fine powder separator from a coarse powder outlet 303 of the fine powder separator at the bottom. The fine powder separated by the fine powder separator, the medium powder separated by the fine powder separator and the coarse powder separated by the fine powder separator may be selectively sent again to the fine powder separator for separation. It should be noted that the above discussion is merely intended to provide a brief description of the separation principles of the fines separator so as to enable one skilled in the art to understand the present disclosure and implement the disclosed system, and that the present disclosure is not so limited.

According to the system disclosed by the invention, in order to fully utilize the raw material of the catalytic cracking catalyst, the system can also comprise a coarse powder grinding unit which can be provided with a coarse powder inlet, a fine powder outlet in the grinding unit and a fine powder outlet in the grinding unit; the coarse powder inlet may be located downstream of the coarse powder outlet of the cyclone and/or the coarse powder outlet 303 of the fines separator 3; the roasting unit 5 can be positioned at the downstream of a powder outlet in the grinding unit, and a fine powder outlet of the grinding unit can be sent to a gelling unit to be used as a catalytic cracking catalyst raw material for gelling. Wherein the milling unit is well known to those skilled in the art and may comprise a milling machine or a shearing machine. The product of the milling process may be classified using additional equipment or may be introduced into the fine separator 3 through the inlet 301 of the fine separator for separation.

According to the system of the present disclosure, the number of the cylinders may be 2 to 3, and the rotation direction of each cylinder may be different, thereby increasing the separation accuracy of the fine powder and/or the sprayed catalyst separated by the cyclone. As shown in fig. 6, 2 cylinders are installed in the fine powder separator 3, fine powder and/or spray catalyst separated by the cyclone separator enters the cylinder 305, and the fine powder and/or spray catalyst separated by the cyclone separator is separated by the stirring sheet 307 inclined on the inner wall of the cylinder and leaves the cylinder 305 from the sieving channel 306. The speed of rotation of the drum 305 and the size of the screening channel can be adjusted to the separation requirements.

According to an embodiment of the system of the present disclosure, the sieving channel 306, the rotating shaft 310 and the cylinder body 305 are collectively referred to as a catalyst agitation mechanism 304, the catalyst agitation mechanism is used to agitate the fines and/or sprayed catalyst entering the cyclone separator at the fines separator inlet 301, such that, the catalyst entering with the conveying wind through the inlet 301 of the fine powder separator is effectively separated from the coarse powder and the fine powder through the action of rotary centrifugal force and air flow under the stirring of the catalyst stirring mechanism 304, wherein in practical application, an air inducing device can be arranged at the downstream of the fine powder outlet 302 of the fine powder separator, to assist the separated fines in the separated fines separator to rise with the gas stream to the top of the housing 300 and exit the fines outlet 302 of the fines separator, i.e. fines can be carried away by the gas flow from bottom to top, while coarser catalyst descends to the bottom of the housing 300 and is discharged from the fines separator's coarse outlet 303.

According to the embodiment of the system of the present disclosure, the catalyst stirring mechanism 304 includes a cylinder 305 rotatably installed in the housing 300 along a vertical axis, a sidewall of the cylinder 305 is spaced apart from a sidewall of the housing 300 and a plurality of sieving channels 306 are respectively distributed along an axial direction and a circumferential direction, that is, the sieving channels 306 have a plurality of sieving channels in the axial direction and the circumferential direction at the same time, and an inward protruding stirring piece 307 is fixed on an inner wall of the sidewall. Therefore, the stirring sheet 307 in the cylinder body 305 can stir the fine powder and/or the sprayed catalyst separated by the cyclone separator through the rotation of the cylinder body 305, at this time, a rotating air flow can be generated in the cylinder body, under the action of a centrifugal force and an air flow formed by the stirring, the coarse powder can be thrown out of the cylinder body 305 through the screening channel 306 and is settled to the coarse powder outlet 303 of the fine powder separator to be discharged, and the fine powder separated by the fine powder separator and the medium powder separated by the fine powder separator can be carried to the fine powder outlet 302 of the fine powder separator and the medium powder outlet 312 of the fine powder separator through the air flow from bottom to top to be discharged, so that the coarse powder separated by the fine powder separator, the medium powder separated by the fine powder separator and the fine powder separated by the fine powder separator can be stirred and separated by the self weight up and down.

According to the embodiment of the system of the present disclosure, the sidewall of the cylinder 305 is formed in a grid structure formed by intersecting the axial rods 308 and the annular rods 309, and the sieving channels 306 are grid holes, so that the formation of the plurality of sieving channels 306 can be realized by a simple structure, and the strength of the structure can be ensured. In other embodiments, the cylinder 305 may be rolled from a single sheet and formed with a plurality of screening channels 306.

In order to achieve the agitation of the fine powder and/or the sprayed catalyst separated by the cyclone, an embodiment is that the agitating blade 307 is formed in a spiral structure extending up and down along the inner wall of the cylinder 305, and when the cylinder 305 rotates, not only can the rotating airflow generated in the cylinder 305 agitate the fine powder and/or the sprayed catalyst separated by the cyclone, but also can make the airflow have a tendency of moving upward to help separate the fine powder separated by the fine powder separator, thereby making the classifying effect of the fine powder and/or the sprayed catalyst separated by the cyclone better. The stirring piece 307 in this embodiment may be one or more. Another embodiment is that, as shown in fig. 5, the stirring piece 307 is a plurality of pieces, and each of the stirring pieces 307 is a structure formed on a plane and is respectively arranged obliquely at an angle to the axis of the cylinder 305. So that an upward flow of air can also be formed in the cylinder 305 to separate the fine powder separated by the fine powder separator when the cylinder 305 rotates. Specifically, the stirring blade 307 is angled at 30-60, such as 45, to the axis of the barrel 305. It is also preferable that the stirring pieces 307 are respectively located on a plurality of planes parallel to each other, that is, the planes on which the stirring pieces are located are parallel to each other, so that an air flow can be formed in the height direction in the cylinder 305 by the stirring pieces arranged at intervals in the axial direction of the cylinder 305, so as to improve the effect of throwing out the coarse powder separated by the fine powder separator and the effect of separating the fine powder separated by the fine powder separator.

According to an embodiment of the disclosed system, as shown in fig. 5, the cylinder body 305 is mounted to the top wall of the housing 300 by a rotating shaft 310 along a vertical axis, and the rotating shaft 310 is connected to the cylinder body 305 by a plurality of connecting columns 311. This allows for both rotation of the cylinder 305 along a vertical axis and a simplified construction so that fines and/or sprayed catalyst separated by the cyclones can enter and exit the cylinder 305 through the gaps between the plurality of connecting columns 311. In other embodiments, the cylinder 305 may also rotate along the vertical axis by various ways such as chain transmission, gear transmission, etc., and the rotating shaft 305 may rotate at a speed of, for example, 300-.

In order to realize more multi-stage separation of the fine powder and/or the sprayed catalyst separated by the cyclone, as shown in fig. 4, the fine powder separator 3 is provided with two fine powder outlets 302 of the fine powder separator, one medium powder outlet 312 of the fine powder separator, two fine powder outlets 302 of the fine powder separator and one medium powder outlet 312 of the fine powder separator, which are sequentially spaced in the height direction on the sidewall of the housing 300.

According to the embodiment of the system disclosed by the invention, as shown in fig. 4, the housing 300 comprises a cylindrical section 313 and a conical section 314 which are connected up and down, the fine powder separator inlet 301 is positioned on the side wall of the cylindrical section 313, the fine powder outlet 302 of the fine powder separator and the medium powder outlet 312 of the fine powder separator are positioned on the side wall of the cylindrical section 313 opposite to the fine powder separator inlet 301, and the coarse powder outlet 303 of the fine powder separator is positioned at the bottom conical tip of the conical section 314, so that the accumulation of coarse powder in the housing 1 is avoided. In addition, the fine powder separator inlet 301 is located between the fine powder outlet 302 of the uppermost fine powder separator and the coarse powder outlet 303 of the fine powder separator, and the ratio of the vertical distance between the fine powder separator inlet 301 and the fine powder outlet 302 of the uppermost fine powder separator to the vertical distance between the fine powder separator inlet 301 and the coarse powder outlet 303 of the fine powder separator is 1:1 to 1:6, preferably 1:3 to 1:6, to better accomplish the discharge of the fine powder.

In a specific embodiment, the system further comprises a molecular sieve preparation unit, the molecular sieve preparation unit comprises a molecular sieve ion exchange unit G1, a filtration unit G2, a flash drying unit G3, a second bag-type dust collector D2 and a second roasting unit E2, and the second bag-type dust collector D2 is the bag-type dust collector provided by the present disclosure; the material inlet of the filtering unit G2 is positioned at the downstream of the material outlet of the molecular sieve ion exchange unit G1, the material inlet of the flash drying unit G3 is positioned at the downstream of the material outlet of the filtering unit G2, the feed inlet of the second bag-type dust collector D2 is positioned at the downstream of the material outlet of the flash drying unit G3, the material inlet of the second roasting unit E2 is positioned at the downstream of the discharge outlet of the second bag-type dust collector D2, and the material outlet of the second roasting unit E2 is positioned at the upstream of the material inlet of the colloid forming unit A. Specific operating steps using a molecular sieve preparation unit may include: feeding crystallized product obtained by hydrothermal crystallization of a crystallization reaction kettle, such as NaY molecular sieve, into a molecular sieve ion exchange unit G1 for ammonium exchange to remove Na ions in the NaY molecular sieve, feeding the ammonium exchanged molecular sieve and exchange liquid into a filtering unit G2 for filtering treatment to obtain filtered NH₄Y molecular sieve, to NH₄And the Y molecular sieve is sent to a flash drying unit G3 for flash drying to further remove moisture in the Y molecular sieve, then the Y molecular sieve passes through a second bag-type dust collector D2 and enters a second roasting unit E2 for roasting, and the roasted product serving as a catalytic cracking raw material is sent to a gelling unit for gelling. The molecular sieve is conveyed by the second bag-type dust collector, so that dust in the conveying gas can be removed and discharged, explosion caused by too small air induction amount of a roasting unit and difficulty in treatment caused by too hard catalyst dust can be prevented, and the discharged gas can meet the smoke (dust) dust concentration of less than 100mg/m in the emission standard of industrial furnace atmospheric pollutants (GB9078-1996) formulated by the air pollution prevention and control Law of the people's republic of China³And (5) primary environmental protection standard.

The present disclosure is further illustrated by the following detailed description, but is not to be construed as being limited thereby.

As shown in fig. 1, the bag-type dust collector includes a casing 1, the casing 1 has a feed inlet 2, the casing 1 further has an air outlet 3 at the top and a discharge outlet 4 at the bottom, and a plurality of bags 52 are vertically installed in the casing 1, wherein one end of each bag 52 is disposed at the top end of the casing 1, the other end of each bag 52 is disposed on a partition plate 6 obliquely disposed in the casing 1 and hermetically connected with the inner periphery or the outer periphery of an opening 61 formed in the partition plate 6, a bag support tube 51 is disposed in each bag 52, the upper end of each bag support tube 51 is connected with the top end of the casing 1, and the lower end of each bag support tube 51 is disposed above the opening 61 of the. The lower surface of the partition plate 6 is provided with a certain number of wind-shielding sheets 7. The cross section of the shell 1 can be round, square or round, preferably round, more preferably, the upper part is a cylinder section 13, the lower part is a cone section 14, the diameter of the cylinder section 13 is 1-5m, the total height of the cylinder section 13 and the cone section 14 is 5-10m, the angle formed by the connecting line of the distance between the feed inlet 2 and the air outlet 3 and the horizontal plane is 45-70 degrees, and the ratio of the vertical distance between the feed inlet 2 and the air outlet 3 to the vertical distance between the feed inlet 2 and the discharge outlet 4 is 1: (2-4). The cross section of a cloth bag 52 in the shell 1 is circular, filter holes are uniformly arranged on a cloth bag supporting tube 51 every 0.05m, the aperture of each filter hole is 0.1-1mm, the height of each filter hole is 1.5-4m, the inner diameter of the cloth bag 52 is 10-200mm, the height of each filter hole is 2-5m, the number of the filter holes is 50-500, the inclination angle of an inclined clapboard 6 can be 20-60 degrees, the clapboard 6 is welded with the shell 1 to form a sealing shape, as shown in figure 2, the diameter of an opening 61 on the clapboard 6 is 10-200mm, a wind shield sheet 7 is vertically welded below the clapboard 6, the wind shield sheet 7 is in a strip shape, the length is 0.1-0.5m, the height is 0.2-0.8m, the number of the wind shield sheets changes along with the size of a cloth bag dust collector, and the number of the wind shield.

A spiral coil pipe type blanking pipe 9 is arranged in the lower chamber 12 of the shell and 0.5-1m away from the lower part of the partition board, the spiral coil pipe is a stainless steel pipe with the inner diameter of 0.2-0.5m, one end of the stainless steel pipe is connected with the feed inlet 2, the other end of the stainless steel pipe is connected with the position 0.5-1m above the discharge outlet 4, the stainless steel pipe is placed along the inner wall of the shell 1 as far as possible, the distance between the stainless steel pipe and the inner wall of the shell 1 is 0.2-1m, the helix angle is 20-45 degrees, a certain number of vent holes 91 are distributed on the pipe wall of the stainless steel pipe, the vent holes 91 are uniformly arranged on the pipe wall of the stainless steel pipe at intervals of 0.1-0.5m, the vent holes 91 can be in any shape and any size, preferably circular vent holes are.

Through above-mentioned technical scheme, the delivery air carries the catalyst and gets into spiral coil, and spiral coil effectively utilizes the whole space of casing, increases catalyst and air at the sack cleaner dwell time, improves the effect of sack cleaner. The air delivery carries the catalyst of certain quantity to discharge from the ventilation hole 91 that spiral coil opened, the air delivery carries the catalyst and collides with windshield 7, make large granule catalyst fall into discharge gate 4 downwards earlier, all the other small granule catalysts get into several sack stay tubes 51 and sack 52 through the induced air and carry out the filtration separation, after sack 52 adsorbs the small granule catalyst of certain quantity, the small granule catalyst reunites the back and drops to discharge gate 4 downwards, the catalyst reaches the effect of detaching the dust like this, the gas of separation reaches the standard that the environmental protection discharged.

The present disclosure is further illustrated by the following examples, but is not limited thereby.

Examples

As shown in FIG. 1, the catalyst at 350 ℃ was fed in an amount of 1000Kg/h and 40m³The air quantity of the (STP) enters the bag-type dust collector from the feeding hole 2 together, wherein the bag-type dust collector shell 1 comprises a cylindrical section 13 and a conical section 14, the diameter of the cylindrical section 13 is 2.8m, the height of the cylindrical section is 5m, the height of the conical section is 3m, the discharging hole 4 is positioned at the bottom conical tip of the conical section, the feeding hole 2 is positioned at the side surface of the cylindrical section, the vertical height from the discharging hole 4 is 2m, the air outlet is positioned at the top of the cylindrical section, and the angle formed by the connecting line of the distance between the feeding hole 2 and the air outlet 3 and the horizontal plane is 60 degrees. The diameter of the cloth bag 52 in the shell is 150mm, the number of the cloth bags is 50, the cloth bags are uniformly arranged in the space above the shell 1 and the partition plate 6, the inner diameter of the cloth bag support pipe in the cloth bag 52 is 120mm, the outer diameter of the cloth bag support pipe is 130mm, and filter holes are uniformly arranged on the cloth bag support pipe 51 every 0.005mThe aperture of the filtering hole is 0.5mm, and the cloth bag supporting tube is 0.1m higher than the cloth bag wrapped outside the filtering hole. The inclination angle of baffle 6 is 45, and thickness is 15mm, and the height that the center department apart from the drum section top is 2.5m, and the quantity of the trompil 61 that sets up on it is 50, and the diameter is 160mm, evenly places 50 on the baffle on the border of trompil 61 is followed to windshield 7, and windshield 7 width 0.1m, height 0.5m, and align to grid links to each other with the spacer is perpendicular. Wherein the unloading pipe 9 of the installation spiral coil pipe form in the casing inside and apart from baffle lower part 0.5m, the spiral coil pipe adopts nonrust steel pipe to constitute, nonrust steel pipe internal diameter 0.3m, development length is 20m, nonrust steel pipe one end is connected feed inlet 2, the other end is connected discharge gate 4 upper portion 0.5m department, nonrust steel pipe is placed as far as possible along casing 1 inner wall, with casing 1 inside distance 0.5m, and the helix angle is 30, distribute certain quantity of ventilation hole 91 on the nonrust steel pipe wall of spiral coil pipe simultaneously, the ventilation hole is evenly arranged at nonrust steel pipe upper wall every 0.2m, the percent opening is 70%, the ventilation hole is circular, internal diameter 0.1m, be used for discharging the defeated air supply that carries the catalyst transport. The catalyst falls into a lower storage tank from a discharge port 4 by the discharge amount of 985 Kg/h-1050 Kg/h, and air is directly led out of the shell 1 by an air outlet 3 positioned at the top of the shell 1, wherein the air lead-out amount is basically 40m³H, so as to prevent the bag from swelling and exploding.

The time for replacing the cloth bag of the prior industrial cloth bag dust remover is about 15 days to 1 month on average under the same treatment capacity (from the replacement of the first cloth bag to the replacement of the whole cloth bag); in the embodiment, the cloth bag replacement time is averagely 3 months to 6 months (from the replacement of the first cloth bag to the replacement of the whole cloth bag), and the discharged air can reach the smoke (dust) dust concentration of less than 100mg/m in the emission standard of industrial furnace atmospheric pollutants (GB9078-1996)³The first-level environmental protection standard.

Claims

1. A bag-type dust collector is characterized by comprising a shell (1), and a partition plate (6) and a plurality of bag supporting pipes (51) which are arranged in the shell (1), wherein the outer side of each bag supporting pipe (51) is wrapped with a bag (52), and the pipe wall of each bag supporting pipe (51) is provided with a filtering hole; the inner space of the shell (1) divided by the partition plate (6) is an upper cavity (11) and a lower cavity (12), an air outlet (3) is formed in the shell (1) where the upper cavity (11) is located, and a feeding hole (2) and a discharging hole (4) are formed in the shell (1) where the lower cavity (12) is located;

the partition plate (6) is provided with a plurality of open holes (61); each cloth bag supporting pipe (51) is connected with the top wall of the shell (1), the upper end of each cloth bag supporting pipe (51) is sealed, the lower end of each cloth bag supporting pipe (51) is arranged above one opening (61) and a cloth bag (52) wrapped outside the corresponding cloth bag supporting pipe (51) is connected with the inner circumference of the opening (61) in a sealing mode, and the feed port (2) and the air outlet (3) are communicated with the opening (61), the cloth bag supporting pipes (51) and the cloth bag (52) in the shell (1) in sequence;

a discharging pipe (9) is arranged in the lower cavity (12), one end of the discharging pipe (9) is connected with the feeding hole (2), the other end of the discharging pipe extends downwards towards the discharging hole, and a ventilation hole (91) is formed in the pipe wall of the discharging pipe (9).

2. Bag-type dust collector according to claim 1, characterized in that the blanking pipe (9) is a spiral coil.

3. The bag-type dust collector according to claim 2, wherein the spiral axis of the spiral coil is arranged in a vertical direction, and the helix angle is 20-45 °.

4. The bag-type dust collector according to claim 1, wherein the other end of the blanking pipe (9) is arranged above the discharge port (4) at intervals, and the vertical distance between the discharge end of the blanking pipe (9) and the discharge port (4) accounts for (0.05-0.2) of the vertical distance between the feed port (2) and the discharge port (4): 1.

5. the bag-type dust collector according to claim 1, wherein the inlet (2) is located on the side wall of the housing, the outlet (3) is located on the top wall of the housing, and the angle formed by the line connecting the distance between the inlet (2) and the outlet (3) and the horizontal plane is 45-70 °.

6. Bag-type dust collector according to claim 1, characterized in that the baffle (6) is arranged obliquely rising from the side of the inlet opening (2) in the housing (1) to the opposite side of the inlet opening (2).

7. The bag-type dust collector according to claim 6, wherein the bottom surface of the baffle (6) forms an angle with the horizontal plane in the range of 20-60 °.

8. The bag-type dust collector according to claim 1, wherein the baffle (6) is provided with a wind shielding sheet (7) protruding downwards, and the wind shielding sheet (7) is a long strip structure vertically extending downwards from the bottom surface of the baffle (6).

9. The bag-type dust collector according to claim 1, wherein the housing (1) comprises a cylindrical section (13) and a conical section (14) which are arranged up and down, the feeding port (2) is located on the side wall of the cylindrical section (13), and the discharging port (4) is arranged at the bottom conical tip of the conical section (14).

10. Bag-type dust collector according to claim 9, characterized in that the ratio of the vertical distance between the inlet opening (2) and the outlet opening (3) to the vertical distance between the inlet opening (2) and the outlet opening (4) is 1: (1-4).

11. A catalytic cracking catalyst preparation system, comprising: a gelling unit (a), a spray dryer (B), a cyclone separator (C), a first bag-type dust collector (D1) and a first roasting unit (E1), the first bag-type dust collector being the bag-type dust collector of any one of claims 1 to 10;

the gelatinizing unit (A) is provided with a material inlet and a material outlet, the spray dryer (B) is provided with a material inlet and a catalyst outlet, and the cyclone separator (C) is provided with a catalyst inlet, a coarse powder outlet and a fine powder outlet;

the material inlet of the spray dryer (B) is positioned at the downstream of the material outlet of the colloid forming unit (A), the catalyst inlet of the cyclone separator (C) is positioned at the downstream of the catalyst outlet of the spray dryer (B), the feed inlet of the first bag-type dust collector (D1) is positioned at the downstream of the coarse powder outlet of the cyclone separator (C), and the inlet of the first roasting unit (E1) is positioned at the downstream of the discharge outlet of the first bag-type dust collector (D1).

12. The system of claim 11, wherein the system further comprises a fines separator (F), the fines separator (F) comprises a housing (300), the housing (300) has a fines separator inlet (301), the housing (300) further has a fines outlet (302) of the fines separator at an upper portion of the housing, a fines outlet (303) of the fines separator at a bottom portion of the housing and a middlings outlet (312) of the fines separator at a middle portion of the housing, and at least one coaxial cylinder (305) rotatably mounted in the housing (300) along a vertical axis is mounted in the housing (300), the side walls of the cylinders (305) and the side wall of the outermost cylinder (305) and the side wall of the housing (300) are spaced apart, and a plurality of screening channels (306) are distributed in each of the cylinders (305) in axial and circumferential directions, stirring sheets (307) protruding inwards are fixed on the inner walls of all the cylinders (305);

the fines separator inlet (301) of the fines separator (F) is located downstream of the fines outlet of the cyclone (C); the inlet of the first roasting unit (E1) is located downstream of the fines separator coarse powder outlet (303).

13. The system of claim 12, wherein the system further comprises a molecular sieve preparation unit comprising a molecular sieve ion exchange unit (G1), a filtration unit (G2), a flash drying unit (G3), a second bag-type dust collector (D2) and a second roasting unit (E2), the second bag-type dust collector (D2) being a bag-type dust collector of any one of claims 1-11;

the material inlet of the filtering unit (G2) is located at the downstream of the material outlet of the molecular sieve ion exchange unit (G1), the material inlet of the flash drying unit (G3) is located at the downstream of the material outlet of the filtering unit (G2), the feed inlet of the second bag-type dust remover (D2) is located at the downstream of the material outlet of the flash drying unit (G3), the material inlet of the second roasting unit (E2) is located at the downstream of the discharge hole of the second bag-type dust remover (D2), and the material outlet of the second roasting unit (E2) is located at the upstream of the material inlet of the colloid forming unit (A).